Neoadjuvant rectal score in prognostic prediction of clinical stage Ⅲ middle-low rectal cancer / 中华放射肿瘤学杂志

ABSTRACT

Objective To investigate the effects of downstaging and neoadjuvant reetal(NAR) score on the prognosis of patients with clinical stage Ⅲ middle-low rectal cancer undergoing preoperative concurrent chemoradiotherapy.Methods From 2006 to 2014,195 patients who were admitted to our hospital and diagnosed with clinical stage Ⅲ middle-low rectal cancer by pelvic magnetic resonance imaging or computed tomography were enrolled.All patients received preoperative radiotherapy with doses of 42-50.4 Gy (median50 Gy,93.8％ of patients received doses of ≥ 50 Gy) and concurrent chemotherapy with capecitabine ± oxaliplatin.Total mesorectal (R0) excision surgery was performed at 4-15 weeks (median7 weeks) after concurrent chemoradiotherapy.The effects of downstaging (stage yp0-Ⅱ) and NAR score (calculated based on cT staging and ypT/N staging) on the prognosis were evaluated.The 3-year disease-free survival (DFS) rate was calculated using the Kaplan-Meier method and analyzed by log-rank test.Results In all the patients,the median follow-up time was 44 months (6.7-125.5 months);the 3-year DFS rate was 76.8％.Downstaging after preoperative chemoradiotherapy was a significant prognostic factor for the 3-year DFS (92.2％ vs.56.8％,P=0.000).The median NAR score was 15.0(0-65.0) in all the patients.Patients with NAR scores of ≤ 15.0 had significantly improved 3-year DFS than those with NAR scores of＞15.0(90.1％ vs.57.0％,P=0.001).In patients with downstaging,those with NAR scores of ≤8.4 had significantly improved prognosis compared with those with NAR scores of＞ 8.4(95.1％ vs.87.5％,P=0.022).Conclusions Patients with downstaging after preoperative concurrent chemoradiotherapy for stage c Ⅲ middle-low rectal cancer have satisfactory prognosis.The NAR score is an effective prognostic predictor.